Russell william mumford



l UNITED STATES PATENT OFFICE.

RUSSELL WILLIAM MUMFORD, OF NEW YORK, N. ASSIGNOR TO REFINING PRODUCTS CORPORATION, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE.

PROCESS OF MAKING SUGAR.

N 0 Drawing.

To all whom it may concern:

Be it known that I, RUSSELL WILLIAM Mmuronn, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Processes of Makin Sugar, of which the following is a speci cation.

This invention relates to processes of making sugar; and it comprises a method of treating sugar liquors, syrups, molasses and all other saccharine solutions wherein a sugar juice or solution, with or Without a preliminary purification, is treated with a particular type of vegetable carbon having the power of taking gummy and coloring matter out of solution and also having the power of taking up or flocculating fine suspended matter, the solution being thereafter evaporated to produce crystallizatlon, such vegetable carbon being an open-textured and porous rather coarse material produced by slow carbonization of various vegetable mattersin the presence of sufficient oxidizing'gases to keep the pores open and free of carbon deposits; all as more fully hereinafter set forth and as claimed.

Stated in 'broad terms, the process of manufacturing sugar from vegetable materials consists in evaporating a solution, such as a vegetable juice, containing the same,

until it is so concentrated that sugar crystallizes out and the main problem before the manufacturer, aside from evaporation, is that of clarifying, purifying and decolorizing his solutions. Vegetable juices and saps, such as those obtained from sugar cane, sorghum, beets, etc., of course contain very many things other than sugar, albuminoids, amids, salts, coloring matter, gums, etc. Not all these matters which must be removed as far as possible for efficient and economical working are in solution; much of the impurity is in suspension and .in the colloidal forms of solutions that approach suspensions. In a general way it may be said that these colloidal and suspended matters are very detrimental since they impede the crystallization.

In the manufacture of sugar from sugar cane, and also from sorghum, the juice is expressed from'the cane by means of cane crusher-s and rollers in ways unnecessary to detail here. To this juice, which is a turan liquid containing suspended fragments of cane, etc., is added lime, to effect the Specification of Letters Patent. Patented Aug. 26 1919 Application filed June 29, 1917. Serial No. 177,820.

neutralization of the natural acidity of this juice, and the mixture is then heated to a temperature of about 98 C. (200 F.), up to the so-called cracking point.

lVhenthis point has been reached, a part of the impurities in the juice rise to the surface as a scum, and the remaining impurities, in greater part, settle to the bottom of the vessel'in which the reaction is carried on. Sometimes a little acid phosphate is employed, together with the lime, in order to produce a greater separation. In some raw sugar factories the scum thus formed is brushed off and the juice is clarified further by additional boiling and brushing. In many plants, however, the liquid juice is, after heating, allowed to settle in special defecation tanks and the clarified juice is decanted from the impurities; these are known as scum, mud, or slops. These scums and deposits are then sent through a mudpress, which retains them as press cakes, and the juice flowing therefrom is added to the clarified juice previously decanted. Separation of the mechanical impurities in the brief time permitted is not complete; it is rare that the juice goes to the evaporaters in an absolutely bright and clear condition. This preliminary purification treatment or defecation, does not remove any large amount of the impurities or the coloring matter. Gummy soluble impurities are not affected to any extent. After evaporation the dissolved and the mechanical impurities of course remain in the thick syrupy product from which'it is now difficult to separate them.

The next step in the process of making raw cane sugar is the concentration of the clarified juice by evaporation under a vacuum into a fairly thick syrup. This syrup is finally evaporated to crystallization; and the thick magma of sugar crystals and molasses is then separated in centrifugals, etc.

In the manufacture of raw sugar from the sugar beet, the sugar beets, after having been thoroughly cleaned and Washed, are sliced into thin, narrow strips called cossettes: these are placed in diffusion batteries and the sugar in them is extracted with hot water. The sugar solution thus obtained is known as diffusion juice. This diffusion juice. after being subjected to one or more processes of purification, is concentrated to the so-called thick liquor which is then boiled to crystallization. The magma of bleaching:

' quality either in time's raw Washing plantation White sugar. rectly converted into white sugar for the market by operations involving chemical Ordinarily, however, raw cane sugar and raw beet sugar are redissolved in water and submitted to refining.

. In refining sugar, whether'raw cane sugars or rawbeet sugars be used, the dissolved or melted raw sugar is usually defecated and so i ' The resulting are known to remove clarified by the use of lime and soluble monocalcium phosphate, or phosphoric acid; the resultant precipitate, which holds imprisoned in it most of the mechanically suspended impurities, is removed by passing I the liquid through either filter bags or filter presses. Sometimes kieselguhr is used as a filtering agent in these refining operations. brown sugar solution. is then led through boneblack cylinders in order to remove color and impurities, and is then further concentrated by evaporation. It is sent to vacuum pans where it is boiled to crystallization. i

., 1 have found, that iii submit thei juices or semi-syrups produced to the action ot. a particular material, which I may here call a decolorant, I can not only remove the dissolved impurities, and particularly the colorgiving impurities, but also the suspended impurities and the quasi-dissolved .or suspended colloids in one operation. Many kinds of carbon, as in the case of boneblack, dissolved matter from sugar juice and enhance its purity Some syrup sufiiciently colorized toallow its being sent to the grainhighly porous are known as bright liquors,

like kies'elguhr -(diatonaceous earth), have another and different action on'sugar uices.

- in that they remove the materials which are clear or what. while they have practically no effect on the dissolved or quasi-dissolved matter. I have found that with my decolorant I can unite both these actions, removing at once the dissolved impurities and the suspended or quasi-suspended colloid materials from sugar solutions; producing in one operation a clarified, purified and destrictly in suspension, giving ing pan to produce directly sugars of a refined type. In other words, I simultane ously decolorize and produce bright liquor,

cane sugar is submitted to drastic and other treatments to give a. In beet sugar factories, the raw sugar is sometimes dience of the grained vegetable matter.

non-carbonaceous materials,.

obtaining in one operation two distinct results, and also effecting a marked economy, or what is the same thing, increasing the capacityof the factory. The present methods of producing sugar require many hours to produce the results that in the present method are produced in an hour.

This decolorant I produce by a special method of charring vegetable matters, such as peat or sawdust, as more fully set forth in my copending. application, Serial No. 167,971. Briefly stated, the method as disclosed in the said application in an advantageous dust or other vegetable matter with a highly colloid material, like starch, in the eventthat such vegetable material does not already contain a suflicient amount of colloid .materials. The vegetable material in a granulated form is then mixed with grains of a material, such as dolomite, adapted to act as a spacing agent and also to evolve carbon dioxid or other purifying gas continuously throughout a wide temperature range. The mixture is then slowly heated in a vented retort. Under the action ofthe heat, the moisture is first expelled, taking; with it various volatile matters and puiiin'g up the vegetable material and rendering it porous. Then the materialchars-slightly, giving off various vapors and gases. Be-

embodiment, is totreat peat or sawcause of the presence of the mineral spacing agent, these vapors and gases are afiorded an opportunityto escape without in their. turn undergoingdecomposition in the'presthe charring goes on" the dolomite begins to evolve carbon dioxid at a temperature some; 1 v

, o where around 250 C. This carbon dioxid is taken up in the pores of the charring mass and'as the temperature goes up, it exercises a beneficial action on these pores, probably by opening them up. The temperature is then carried to a high point and the material is dumped into water and washed. The ultimate material is a granu' lar carbon havingopen pores representing,

--more or less closely, the cellular structure of the original material before carboniza-' tion. It is more open-textured than charcoal in which, in the usual methods of making charcoal, the pores are more or' less closed and sealed by the deposition of carbon in them. When wood is first charred in making charcoal, the vapors and gasesaccumulate in the pores where they'are in turn carbonized,.depositing what may be termed seethe pores and tending to ondary carbon in close such pores. This is desirable in making charcoal where a hard, dense product is wanted. In the present material, the effort is to have open pores substantially free of secondary carbon and capable of collecting sus ended solids. e

s I have found, a

carbon prepared as but if heating to say 85 described when added to sugar solutions and syrups takes the coloring matter out of solution and also attracts or flocculates sus;,

pended and quasi-suspended impurities.

In a practical embodiment of the present process of making. cane sugar, cane juice may first be obtained and defecated in the usual ways as hereinbefore set forth, and then concentrated by evaporation to produce a syrup. I may, but less advantageously, dispense with this preliminary evaporation or concentration and .treat the juice as it comes from the press%, but ordinarily I concentrate the juice to syrup or semi-syrup prior to applying the present process.

The syrup does not need to be sipeclally acidified when my decolorant is ad ed and no heating to any particular degree or boiling is essential, but the solution must not be alkaline. My decolorant acts effectively on cold neutral and non-acidified solutions, C. or 90 C. or acidifying is deemed advantageous in the general manufacturing process of the raw sugar or is deemed necessary to expedite subsequent filtration, it may be done.

After thoroughly mixing my decolorant with the syrup, the agitation may be continued for some time, say about from 10 to 15 minutes, either by stirring or by the use of an air blast. The mixed solution should then be sent through a filter press.

The filtered juice will be then found to be very light in color; all, or nearly all, of its color having been removed. It is not merely bleached, because my decolorant actually retains the coloring matters. The decolorant also takes up the gummy and dissolved impurities which retard crystallization in the ordinary methods. And it takes up in some manner all the suspended materials so that the filtered material is absolutely bright.

The filtered, bright, clear juice may be sent to the graining apparatus and evaporated down to crystallization, giving a white sugar fit for direct consumption. In the manufacture of so-called plantation white sugars my decolorant is best applied to a syrupy'f liquid, as above described.

It is possible however, although less advantageous,' to use'the decolorant at other stages; that is, prior to a concentration to a syrupy product. It may, for example, be ap plied to a .juice which has undergone the usual. defecation and clarifying treatments; to the juice as it comes from the 'defecators and before it goes to the evaporators. It. is

,"even possible to use my decolorant with the raw cane juice at the time, or prior to the time, of liming the juice, but although there is thus obtained at once a clarified juice much brighter. purer and much lighter in color than could otherwise be obtained, I do not deem it so advantageous to add the decolorant at this stage for two reasons. In

' the first after place, not all of the purifying and decoloriz ng power of'my decolorantis utilized, owing to the envelopment of the particlesby clogging impurities; in the second place, recovery of the decolorant for fluther use is commercially much more difiicult on account of the many impurities with which it becomes mingled.

To recover my material, the cakes decolorant formed in the first thoroughly sweetened off, by hot water, in the presses. The cake is then removed from the presses and the material boiled with a Wea solution of caustic soda of, say, 2 to 10 per cent. in strength. This treatment extracts principally the coloring matters which the decolorant has taken up from the sugar solutions. Finally, the decolorant is treated with dilute hydrochloric acid, in strength and amount sufficient to remove all the caustic soda remaining in the decolorant. Another thorough washing with water follows, washing being continued until all of the salt formed and any free acid which may have remained have been removed. The material can then be dried and it is ready for use again. Or the drying may be omitted and the wet material used directly.

In the treatment of beet uice, the juice may be obtained and purified or defecated as hereinbefore described. It is best to add the decolorant to the somewhat concentrated or evaporated and syrupy material obtained the usual defecating and clarifying steps hereinafore described. I may use, as before, the raw juices, or I may use the clarified juice prior to any concentration, but I find it best to work with the more or less concentrated or syrupy material. To the juice or the syrupy material, I add my de-, colorant and agitate thoroughly for some time, say about from 10 to 15 minutes. Mechanical agitation of any suitable type may be used; or agitation may be by air blown in. My decolorant acts on cold non-acidified or neutral solutions, but the juices or syrups may be acidified and heated to 85 C. or 90 C. if deemed advisable for any reason. The mixture of juice and decolorant is then sent through filter presses, and thence goes to the vacuum pan in the manner stated in regard to the manner of making cane sugar.

The sugar juices coming from the filter press will be found to be absolutely water white in color. No bleaching by sulfur in any form, hyposulfites, ozone, etc., is required. And the sugar after having been crystallized will have no tendency toward going off in color. Recovery of my decolorant and its revivification by washing are of course exactly as before described.

My decolorant may be used in refining raw sugars, being dissolved or melted in the blow ups as h 1 'cinbefore described. However. in using tiev present method emit is to be thoroughly lar high temperature or to ployment 'ofphosphoric acid or phosphates or .kieselghur may be entirely obviated. With the solution is mixed my decolorant; ten to fifteen minutes under constant" stirring or agitation being allowed for the action-of the decolorant. The sugar solution during this time is kept under the temperature conditions usual in blow-up work, but no acidifying .of the solution is necessary nor is the attainment of any particular degree of heat. If however acidification is desired for other reasons, it may be resorted to, but I desire it to be understood that it is not necessary to acidify the sugar solution in order to obtain the decolorizin action of my decolorant. The use of bleac ing acids is neither essential nor desirable, nor is it essential to heat the solution to any particuboil it. Acidification or heat is not necessary although both or. either may be employed if desired. The solution containing the decolorant is finally sent through a fil'ter press to recover the decolorant. The decolorant is then subsequently revivified by washing, etc.,. as before described,

. it is desired to use'the customary treatmeat with phosphoric acidor monoca'lcium phosphate and mllk of lime followed by kieselguhr, this may be done. In this event, I advantageously add my decolorant to the sugar solution after it comes from the filter bags or filter presses, and just before it is sent on to the boneblack cylinders. The added decolorant should be allowed 10 to 15 minutes for its action durin which time mixed with the sugar solution under constant stirring or agitation. If desired a hose with compressed air may be used to keep the solution uniformly agitated for the purpose of mixing the decolorant therewith.

I desire it. to be distinctly understood that no acidifying of the solution is necessary in order to obtain a decolorizing action with the present decolorant or in order to set up a bleaching action by such acid, and no particular\ degree of heat or boiling is required in order to obtain the desired actions with my decolorant. Acid may however of course be added if the refiner prefers to do so, and the solution -may, if desired, be heated up to about 85 or 90 C.

My process may be applied in one or more stages. As I have just described it, there is but a single treatment with my decolorant, but my decolorant may be very advantageously applied in small quantities at a further station in the process of making sugar, and its use at this second station is advantageous, and particularly withthe thick liquors just before the same are sent to the pan for graining. The use of the decolorant in a plurality of portions at different stages of manufacture is equally useful liquors are the and in refining raw sugar. For example,

the sugar uices after the clarification may be treated with a portion of my'decolorant and separated, be then concentrated to a syrupy condition and more added, and so on. There may be as many of these additions at as many different stages between the juice or solution and the sugar as may be desired. A small percentage of my decolorant on the solids in the solution is usually suflicient, and five minutes ordinarily sufiice for the action of my decolorant in a second application. On subsequent removal of the decolorant by filter press any slight cloudiness of the thick liquors will have entirely disappeared and water white sparkling thick result of the treatment with my decolorant. I desire it to be particularly understood that no acidifying of the solutions is necessary and no special high temperature is required, although acid may be added if the refiner prefers to do so.

While I have hereinbefore described the use of my material particularly with juices and materials containing cane or beet sugar,

yet the present method may also be advantageously used with solutions containing other sugars. It may, for example, be used in whitening and purifying glucose solutions. In so doing, the so-called steeping solutions may be tr'eatedwith my decolorant and the solution then evaporated to a more or less syrupy condition and treated a second time if desired with a small percentage of my decolorant in the manner hereinbefore described. The whitened and brightened syrup may then be sent to the evaporators for final concentration.

The present method obviates the necessity of using sulfur in the sugar industry in any form.- It also renders bleaching agents unnecessary, for the present decolorant actually removes the color, taking it out of the solution instead of merely bleaching it or masking it, as is done by sulfurous acid, tlle sulfites, hyposulfites, ozone, etc., frequently recommended for the purpose. When my decolorant is used there can be no subsequent going off in color as is often found in the final products when bleaching is resorted to. I regard the present process as applicable to any juice or solution containing sugar, whether the same be a raw juice, a clarified juice, a syrup, a. semi-syrup, a molasses or any other form of sugar solution; and the sugar solution to sarily be a solution of sucrose (cane sugar)- it may be a solution of other sugar, glucose, maltose, lactose, etc. In its best embodiment, however, the present process comprises heating such a sugar solution to obtain defecation and separation of the coarse fragments or mechanically suspended impurities as far as possible, and thereafter adding be purified need not neces- V porous open-textured carbon produced by the slow carbonization of. vegetable matter under circumstances maintaining an open unobstructed by secon "ments of mechanically .ties as far as possible,

texture, such carbon having pores substantially unobstructed by secondary carbon and adapted to take up and retain fine insoluble suspended matter, separating the carbon and evaporating the sugar liquids to crystallization. a

2. The process of purifying sugar solutions which comprises heating and defecating the turbid liquid to separate coarse fra suspended impuriadding to the liquid in a neutral condition a porous open-textured carbon produced by the slow carbonization of vegetable matter under circumstances maintaining anopen porous structure, such carbon having ores substantially diary carbon and adapted to take up and retain fine insoluble "suspended matter, separating the carbon and evaporating the liquid to crystallization. 3.- In the purification of sugar solutions toremove dissolved and suspended impurities, the process which comprises vigorously agitating such solutions with a relatively etable carbon having open original texture of the material from which such carbon was made, such carbon havin pores substantially unobstructed by secon ary carbon and adapted to take up and retam fine insoluble suspended matter.

4. In the purification of sugar solutions to remove dissolved and suspended impurities, the process which comprises defecatmg such a solution to remove dissolved and suspended tating the defecate solution with a relatively coarse grained vegetable carbon, having open pores corresponding substantially to the original texture of the materials from which such carbon was made, such carbon havin pores substantially unobstructed by secon ary carbon and adapted to take up and retain fine insoluble suspended matter.

5. In the purification of sugar solutions the process which comprises vigorously agitating such solutions in a thick and syrupy condition with a relatively coarse grained vegetable carbon having open pores correimpurities as far as (possible, vigorously agi- Separated impurities as far spondin substantially to the original texture of t e material from which such carbon was made, such carbon having pores substantially unobstructed by secondary carbon and adapted to take up and retain fine insoluble suspended matter.

6. In the purification of sugar solutions the process w llCll comprises defecating such a solution, removing separated coarse fragments of impurities as far as practicable, mixing the liquid with a porous open-textured vegetable carbon, having open pores corresponding substantially to the original texture of the material from which such carbon was made, such carbon having pores substantially unobstructed by secondary carbon and adapted'to take up and retain fine insoluble suspended matter, the mixing be ing continued for a time under agitation, separating the carbon b filter pressing and evaporatingthe purified liquid to crystallization.

the process whichcomprises vigorously agitating such solutions in a neutral condition with a relatively coarse grained vegetable carbon having open pores corresponding substantially to the original texture of the material fromwhich such carbon was made, such carbon having pores substantially unobstructed by secondary carbon and adapted to take up and retain fine insoluble suspended matter.

8. In the purification of sugar solutions to remove dissolved and suspended impurities, the process which comprises evaporating such solutions to a thick or syrupy condition, vigorously agitating in a neutral condition with a relatively coarse grained vegetable carbon having open pores corresponding substantially to the original texture of the material from which such carbon was made, such carbon having pores substantially unobstructed by secondary carbon and adapted to take up and retain fine insoluble suspended matter.

having open pores corresponding substan- 1 tially to the original texture of the material from which such carbon was made, such carbon having pores substantially unobstructed by secondary carbon and adapted to take up and retain fine insoluble suspended matter, the mixing being continued for a time under agitation, separating the carbon by filter ressing and evaporating the purified liqui .to crystallization.

10. In the purification of sugar solutions 'terial from which such su'chharbon having pores substantially un-V. obstructed by secondary'ca-rbon andadapted to take-up and retain fine insoluble 'susto remove dissolved and suspended impurities, the process which comprises defecating such a solution to remove coarse fragments of separated impurities as far as practica- 'ble', mixing the liquid in aneutra-l condition with a porous open-textured vegetable car bon having open pores corresponding substantially to the original texture of the macarbon was made,

separating the evaporating the purified liquid to a thicker syrup, add1ng a small amount of the open-textured carbon agitating, agaln filter,

to such thicker syrup, pressing, and finally evaporating the resultant clarified and decolorized liquid to crystallization.

hereto.

RUSSELL WILLIAM MUMFORD Y 

